1. Field of the Invention
The present invention is related to a coolant supply apparatus for a cutting tool for cutting a workpiece wherein there is relative cutting motion about an axis of rotation between a cutting member or plate mounted upon a tool shank and a workpiece. The coolant is supplied from a coolant supply means to the cutting member by means of aligned bores in a coolant supply member, coolant supply ring and tool shank.
The present invention is also related to a cutting tool including such a coolant supply apparatus and a flexible valve for use with such apparatus.
2. Description of the Prior Art
Presently, it is known to supply a cooling medium to a rotating cutting tool from a coolant supply means to a cutting member. For example, one known apparatus is described in U.S. Pat. No. 4,392,761 to Eckle. The rotary machinery tool described in the Eckle patent includes a coolant delivery system wherein coolant is supplied from a supply pipe through a series of bores to the cutting plates. The coolant is supplied during the cutting operation. The Eckle apparatus is particularly useful in those applications where the cutting tool performs a number of machining operations one after the other upon the same workpiece. In such operations, different cutting plates are used for different cutting operations on the same workpiece. It is highly desirable to automatically interchange the cutting plates throughout the process. Ordinarily it is necessary to disconnect and then reconnect the coolant supply system each time the cutting plates are changed. An object of the Eckle apparatus is to provide a system of the type described therein which provides automatic coupling of the coolant delivery apparatus during the cutting plate interchanging process. This is done by supplying a cooling medium to the cutting plates using a supply ring which is automatically connected to and disconnected from a coupling head during cutting plate changes. More particularly, when one cutting member has been replaced by another and the tool shank is caused to rotate, the supply ring is designed to rotate in the same direction by the friction between the tool shank and the supply ring which is positioned on the tool shank. In this manner, a sealing surface of a coupling piece radially projecting from the supply ring comes into engagement with a sealing surface of a coupling head so that coolant can pass through bores in the coupling head, coupling piece and supply ring and then on through a bore in the tool shank to the cutting member. However, this apparatus requires that the sealing surfaces be disposed at specifically identified acute angles to assure proper bore alignment and minimize leakage. In addition, the sealing surfaces must be forced or snapped into sealing engagement with each other by the rotation of the tool shank. Since the supply ring rotates as a result of friction between the tool shank and the supply ring, if the sealing surfaces are not properly oriented relative to each other prior to rotation, improper engagement of one of the surfaces by the other will result thereby preventing complete rotation of the ring causing incomplete alignment and undesirable leakage.
It is highly desirable to provide a coolant supply apparatus for a cutting tool which provides automatic coupling and uncoupling of the coolant delivery apparatus during the cutting plate interchanging process which does not require the engagement of specially oriented sealing surfaces to assure proper bore alignment and to minimize leakage. It is also desirable to provide such machinery wherein there is no need to force or snap together the sealing surfaces of a coupling piece and a coupling head in response to rotation of the tool shank.